An optically controlled three-terminal memristor
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-20
- Publication Date
- 2026-08-14
AI Technical Summary
[0004]两端忆阻器结构简单、易于实现高密度交叉阵列集成，但在工程实现中仍存在如下不足：其一，两端器件的读出与写入共用同一对电极，读写过程耦合明显，易产生读扰动与写扰动，难以实现对电阻状态的独立、精细调控；其二，很多两端忆阻器依赖导电细丝形成或断裂或离子迁移实现电阻转换，细丝成核位置与生长路径具有随机性，导致器件间与周期间离散性较大，阈值电压、开关窗口及多级电导状态的可重复性不足；其三，在交叉阵列中易产生旁路电流与半选扰动，常常需要引入选通器件或复杂电路以抑制漏电流，从而增加面积与功耗，并降低集成优势
本发明的光学栅控三端忆阻器利用GeO2对213 nm深紫外光的有效吸收，在MoS2材料层和GeO2材料层的异质界面形成光生电荷积累，并通过光栅控效应对MoS2横向沟道进行非接触式调制，从而实现“入射光—界面电荷—沟道电流”之间的高效耦合。由于上述结构并不依赖大量光生载流子直接跨界面注入MoS2，而是借助界面净电荷对沟道表面势进行调控，因此能够在较低传输损耗下获得明显的电流调制能力，有利于提高器件的灵敏度、开关比以及弱信号响应能力。同时，MoS2作为二维沟道材料，具有原子层级厚度和较高的界面电场敏感性，界面附近少量电荷变化即可引起沟道载流子浓度和输运状态的显著改变，因此相较于常规材料沟道器件更容易获得高增益调制效果。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of memristors, and more particularly to an optically controlled three-terminal memristor. Background Technology
[0002] With the rapid development of complex algorithms such as artificial intelligence and machine learning, the "storage-computation separation" of traditional von Neumann computing architecture in large-scale data processing leads to significant data transfer overhead, making the von Neumann bottleneck increasingly prominent. In scenarios such as data centers, simply increasing clock frequency or continuing Moore's Law is no longer sufficient to simultaneously meet the demands for high throughput, low power consumption, and high parallelism, driving the exploration of new devices, materials, and architectures. Among these, neuromorphic computing, inspired by the information processing mechanisms of the human brain, has attracted attention due to its potential for parallelism, fault tolerance, and low power consumption. Synaptic plasticity is a key foundation for brain-like learning and memory; therefore, devices and systems capable of simulating synaptic behavior are considered an important way to overcome the limitations of traditional architectures.
[0003] Memristors, as novel devices capable of adjustable conductance and storing historical states, are considered one of the key hardware foundations for non-volatile memory and neuromorphic computing. However, existing two-terminal memristors generally suffer from problems such as random formation of conductive filaments, insufficient controllability, poor device consistency and repeatability, and a lack of independent control terminals. Some three-terminal memristors proposed to improve controllability suffer from structural complexity and limited gate control efficiency. Furthermore, in existing memristors with optical response, the photoelectric effect often remains at the level of surface response or simple resistance changes, making it difficult to effectively couple with the memristor mechanism, thus limiting the device's application in multi-dimensional control and functional integration. For these reasons, a novel three-terminal memristor device with a relatively simple structure, rich control dimensions, and the ability to achieve coordinated electrical and optical modulation is needed to meet the application requirements of novel memory and neuromorphic computing.
[0004] Two-ended memristors have a simple structure and are easy to integrate into high-density cross-arrays, but they still have the following shortcomings in engineering implementation: First, the read and write operations of two-ended devices share the same pair of electrodes, resulting in significant coupling during the read and write processes, which easily leads to read and write disturbances and makes it difficult to achieve independent and precise control of the resistance state. Second, many two-ended memristors rely on the formation, breakage, or ion migration of conductive filaments to achieve resistance switching. The nucleation position and growth path of the filaments are random, resulting in large dispersion between devices and between cycles, and insufficient repeatability of threshold voltage, switching window, and multi-level conductance states. Third, bypass current and half-selection disturbances are easily generated in cross-arrays, often requiring the introduction of gating devices or complex circuits to suppress leakage current, thereby increasing area and power consumption and reducing integration advantages.
[0005] Compared to two-terminal memristors, three-terminal memristors typically modulate channel conductance by introducing a gate, which helps to separate read / write paths and improve controllability to some extent. However, existing three-terminal solutions still face the following problems: First, three-terminal structures usually require additional gate dielectric or electrolyte layers and complex multilayer material stacking, resulting in a narrow fabrication process window. Interface defects and material fluctuations can easily introduce threshold drift, hysteresis, and consistency issues. Second, some three-terminal devices rely on mechanisms such as ion gel or electrochemical doping, making them highly susceptible to environmental influences and requiring high long-term stability and packaging. Third, the increased cell area and interconnection overhead of three-terminal devices lead to increased driving and addressing complexity as the array scale expands, hindering the realization of integrated applications that balance high density and low power consumption. Fourth, in existing memristors with optical response, the photoelectric effect is often not fully coupled with the memristor mechanism, manifesting more as drift caused by changes in surface resistance or thermal effects, making it difficult to achieve programmable modulation of the write threshold, conductance window, and retention characteristics. Summary of the Invention
[0006] This invention provides an optically gated three-terminal memristor that combines deep ultraviolet selective response, high-sensitivity channel control, simple structure, and potential for functional expansion.
[0007] This invention provides an optically gated three-terminal memristor, comprising a substrate, an insulating material layer, a MoS2 material layer, a GeO2 material layer, and metal active electrodes. The insulating material layer is disposed on the substrate. The MoS2 material layer is disposed on the insulating material layer. The GeO2 material layer is disposed on the MoS2 material layer, and a heterojunction is formed at the interface between the GeO2 material layer and the MoS2 material layer. Two metal active electrodes are included, both disposed on the MoS2 material layer and on opposite sides of the GeO2 material layer.
[0008] Furthermore, the thickness of the MoS2 material layer is 10 nm.
[0009] Furthermore, the thickness of the GeO2 material layer is 50-1000 nm.
[0010] Furthermore, the thickness of the metal active electrode is 10-1000 nm.
[0011] Furthermore, the metal active electrode includes one of Ag electrode, Au electrode, Cu electrode, and Zn electrode.
[0012] Furthermore, the metal active electrode is an Ag electrode.
[0013] Furthermore, the thickness of the insulating material layer is 100 nm.
[0014] Furthermore, the insulating material layer includes one of the following: SiO2 material layer, Al2O3 material layer, HfO2 material layer, and ZrO2 material layer.
[0015] Furthermore, the insulating material layer is a SiO2 material layer.
[0016] Furthermore, the GeO2 material layer was deposited on the MoS2 material layer by magnetron sputtering.
[0017] The present invention has the following beneficial effects: The optically grating-controlled three-terminal memristor of this invention utilizes the effective absorption of 213 nm deep ultraviolet light by GeO2 to form photogenerated charge accumulation at the heterogeneous interface between the MoS2 and GeO2 material layers. Through the grating control effect, non-contact modulation of the MoS2 lateral channel is achieved, thereby realizing efficient coupling between "incident light—interface charge—channel current". Since this structure does not rely on a large number of photogenerated carriers being directly injected across the interface into MoS2, but rather on the control of the channel surface potential by the net interface charge, it can achieve significant current modulation capability with low transmission loss, which is beneficial for improving the device's sensitivity, on / off ratio, and weak signal response capability. Simultaneously, MoS2, as a two-dimensional channel material, has atomic-level thickness and high interfacial electric field sensitivity; even a small change in charge near the interface can cause a significant change in the channel carrier concentration and transport state. Therefore, compared to conventional material channel devices, it is easier to achieve high-gain modulation effects.
[0018] Furthermore, in the optically gated three-terminal memristor of this invention, oxygen vacancies and related defect states in the GeO2 material layer can capture and release photogenerated electrons or holes, forming an equivalent photogenerated gate voltage with a certain duration near the interface. This allows the device to possess characteristics such as threshold drift, slow recovery, and history dependence, in addition to instantaneous photoresponse, thus providing a good foundation for subsequent expansion into optically controlled memristors, optoelectronic storage, opto-synapses, and neuromorphic devices. The insulating material layer in this invention mainly serves to provide insulation and suppress leakage current, effectively limiting parasitic current paths, stabilizing dark-state backgrounds, and improving device repeatability. The optically gated three-terminal memristor of this invention has a simple and clearly defined structure, avoiding the process burden caused by complex multi-gate structures or additional driving terminals.
[0019] Overall, the optical gate-controlled three-terminal memristor of this invention combines deep ultraviolet selective response, high-sensitivity channel control, simple structure, and potential for functional expansion, making it suitable for applications such as 213 nm deep ultraviolet detection, high-sensitivity optoelectronic switches, and novel optically controlled neuromorphic devices. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the structure of the optically controlled three-terminal memristor in this invention; Figure 2 This is a flowchart illustrating the fabrication process of the optically controlled three-terminal memristor in this invention. Figure 3 This is a diagram of the gate control data of the optically controlled three-terminal memristor in this invention; Figure 4 This is the absorption wavelength diagram of the optically grating-controlled three-terminal memristor in this invention. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Although exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this disclosure and to fully convey the scope of this disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0022] See Figure 1 An embodiment of the present invention provides an optically gated three-terminal memristor, comprising a substrate, an insulating material layer, a MoS2 material layer, a GeO2 material layer, and a metal active electrode.
[0023] The substrate can be N-type silicon (N++). The substrate size can be 2nm × 2nm. The above substrate does not perform active gate control function.
[0024] An insulating material layer is disposed on the substrate. This insulating material layer can be a SiO2 layer, or it can be replaced with one of the following: an Al2O3 layer, a HfO2 layer, or a ZrO2 layer. The thickness of the insulating material layer can be 100 nm. Through this configuration, the insulating material layer acts as a protective layer to achieve electrical isolation, suppress gate leakage and direct carrier injection, improve device reliability (breakdown resistance, stability), and reduce uncontrollable drift caused by gate terminal participation in conduction.
[0025] The MoS2 material layer is deposited on an insulating material layer. The thickness of the MoS2 material layer can be 10 nm. The MoS2 material layer can be deposited on the insulating material layer by magnetron sputtering. A molybdenum disulfide target with a purity of 99.9999% can be used. It should be noted that MoS2 is a two-dimensional channel material and is extremely sensitive to potential changes near the interface.
[0026] A GeO2 material layer is deposited on top of a MoS2 material layer, forming a heterojunction (GeO2 / MoS2 heterojunction) at the interface between the GeO2 and MoS2 layers. The thickness of the GeO2 material layer can be 50-1000 nm, such as 50 nm, 100 nm, 500 nm, 800 nm, and 1000 nm. The GeO2 material layer can be deposited on the MoS2 material layer by magnetron sputtering. The sputtering process causes elemental mixing in the heterojunction structure, increasing the number of defects in the GeO2 / MoS2 heterojunction and optimizing memristor performance. With this setup, amorphous GeO2 exhibits absorption response in the 213 nm solar-blind band, generating photogenerated carriers. Oxygen vacancies, non-stoichiometric defects, and local interface barriers in GeO2 selectively trap one type of carrier. Its oxygen vacancies and trapped states are used to trap charge, forming a net photogenerated charge layer at the interface between the GeO2 and MoS2 material layers, thereby modulating the MoS2 channel layer. Specifically, the net charge layer formed at the interface between the GeO2 and MoS2 material layers will change the surface potential of MoS2 through electric field coupling, which is equivalent to applying a light-triggered gate voltage to MoS2, thereby changing the carrier concentration, Fermi level position, and depletion region width near the source-drain contact in the MoS2 channel.
[0027] The system comprises two metal active electrodes, both disposed on opposite sides of a MoS2 material layer. These metal active electrodes can be Ag electrodes, or alternatively, Au, Cu, or Zn electrodes. The thickness of the metal active electrodes can range from 10 to 1000 nm, such as 10 nm, 100 nm, 500 nm, 800 nm, or 1000 nm. The metal active electrodes can be deposited on the MoS2 material layer via magnetron sputtering. This configuration allows the two Ag electrodes to form a lateral current channel, providing a read or write current path. Under bias, Ag will generate a certain amount of ions or undergo interfacial reactions, participating in the formation of conductive filaments in the MoS2 channel, thereby affecting the threshold and switching window.
[0028] See Figure 2 The present invention provides a method for fabricating the above-mentioned optically controlled three-terminal memristor, comprising the following steps: Step (1) Deposit an insulating material layer on the substrate.
[0029] Step (2) deposit a MoS2 material layer on the insulating material layer by magnetron sputtering.
[0030] Step (3) Deposit a GeO2 material layer on the MoS2 material layer by magnetron sputtering.
[0031] Step (4) Two metal active electrodes are deposited on both sides of the GeO2 material layer on the MoS2 material layer by magnetron sputtering.
[0032] In summary, this invention provides a source of variable conductivity and plasticity through a GeO2 / MoS2 heterojunction, achieves low leakage current through an insulating material layer, and utilizes the GeO2 material layer to programmably control the threshold, window, and hold characteristics at a third end, thereby improving the device's controllability, stability, and multi-level state realization capability.
[0033] Compared to two-terminal memristors, in the optically gated three-terminal memristor of this invention, under 213nm solar-blind illumination, the amorphous GeO2 material layer absorbs photons to generate photogenerated carriers, causing the carriers to localize in the GeO2 material layer. This alters the resistivity of the composite functional layer composed of the GeO2 and MoS2 material layers, enabling optical modulation of the memristor state at the third terminal, reducing read / write coupling, and improving the programmability of multi-level states. Compared to conventional three-terminal memristors, the MoS2 material layer of the optically gated three-terminal memristor of this invention is very thin and has an adjustable bandgap. The electric field is effective for modulation of the entire channel. GeO2 absorbs 213nm light to generate many carriers, thus significantly affecting the MoS2 channel current intensity. Simultaneously, the insulating material layer acts as a gate dielectric layer to provide stable electrical isolation, reducing the risk of gate leakage and breakdown, and improving device reliability.
[0034] Example 1 Step (1) Deposit a 100 nm thick SiO2 material layer on N-type silicon (N++).
[0035] Step (2) A 10 nm thick MoS2 material layer is deposited on the SiO2 material layer by magnetron sputtering.
[0036] Step (3) A 50 nm thick GeO2 material layer is deposited on the MoS2 material layer by magnetron sputtering.
[0037] Step (4) Two 10 nm thick metal active electrodes are deposited on both sides of the GeO2 material layer on the MoS2 material layer by magnetron sputtering.
[0038] Experimental Example 1 Figure 3 This is a gate control data diagram of the optically gated three-terminal memristor in this invention. It shows that under 213 nm solar blind light illumination, with a fixed voltage ranging from -50 V to 50 V, the device performance varies with the incident light power density. It can be seen that the higher the incident light power density, the greater the current between the source and drain.
[0039] Figure 4The absorption wavelength diagram of the optically controlled three-terminal memristor in this invention shows that the photocurrent is relatively high near 213 nm, about 0.011 nA, indicating that the device has the best response in this ultraviolet band. It can also be seen that the current gradually decreases with increasing wavelength and tends to zero after 450 nm, indicating that the device is only sensitive to short wavelengths.
[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. An optically grating-controlled three-terminal memristor, characterized in that, include: Substrate; An insulating material layer is disposed on the substrate; A MoS2 material layer is disposed on the insulating material layer; A GeO2 material layer is disposed on the MoS2 material layer, and a heterojunction is formed at the interface between the GeO2 material layer and the MoS2 material layer; The metal active electrode comprises two electrodes, both of which are disposed on the MoS2 material layer and on both sides of the GeO2 material layer.
2. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The thickness of the MoS2 material layer is 10 nm.
3. The optically controlled three-terminal memristor as described in claim 1, characterized in that, The thickness of the GeO2 material layer is 50-1000 nm.
4. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The thickness of the metal active electrode is 10-1000 nm.
5. The optically controlled three-terminal memristor as described in claim 1, characterized in that, The metal active electrode includes one of Ag electrode, Au electrode, Cu electrode, and Zn electrode.
6. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The metal active electrode is an Ag electrode.
7. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The thickness of the insulating material layer is 100 nm.
8. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The insulating material layer includes one of the following: SiO2 material layer, Al2O3 material layer, HfO2 material layer, and ZrO2 material layer.
9. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The insulating material layer is a SiO2 material layer.
10. The optically grating-controlled three-terminal memristor as described in claim 1, characterized in that, The GeO2 material layer was deposited on the MoS2 material layer by magnetron sputtering.